There are limited data regarding the side branch occlusion (SBO) after Absorb bioresorbable everolimus-eluting vascular scaffolds (BVS) 1.1 (Abbott Vascular, Santa Clara, California). Even though the second-generation BVS 1.1 has improved on the design of BVS 1.0, the increased strut thickness and width remain and potentially more frequently compromise small SB as compared to the new-generation drug-eluting stents with thin strut. A previous study (1) demonstrated that BVS had a higher incidence (10.5%) of post-procedural SBO compared with the everolimus-eluting metallic stent for SB with a reference vessel diameter ≤0.5 mm. Regarding SB with a reference vessel diameter of ≥1.0 mm, however, the incidence of SBO in the BVS group was similar to that in the everolimus-eluting metallic stent group (1.7% vs. 2.2%, p = 0.61).

The current case report demonstrates the interesting finding of SBO after BVS implantation for a bifurcation lesion. A 69-year-old man was referred to our hospital for coronary angiography as he had been experiencing worsening exertional angina. Angiogram revealed a significant stenosis at a bifurcation site in the distal left circumflex artery (Medina class 1.1.1) (Figures 1A and 1B). According to quantitative coronary analysis, RVD and minimal lumen diameter of SB1 was 2.30 mm and 0.82 mm, respectively. A BVS 2.5 × 28 mm was implanted with post-dilation in the main branch using a provisional technique with a guidewire in the side branch. Subsequently, the jailed guidewire in the side branch was removed to reduce the artifacts during optical coherence tomography (OCT), aiming to evaluate the scaffold expansion and apposition. However, angiogram following OCT evaluation revealed a SBO (Figures 1C and 1D). Several attempts to recross with the guidewire through the BVS strut into the SB were unsuccessful. The OCT demonstrated that the orifices of both SB1 and SB2 were completely covered by the BVS struts (Figures 2A to 2C). According to OCT findings, the main cause of SBO in this case may have been the increased BVS strut thickness and width rather than other well-known causes of SB compromise. Previous studies suggested several potential mechanisms for SBO, including the presence of ostial stenosis in the SB, dissection, plaque, and carina shift (2,3). In this case, however, the BVS struts alone appear to be the cause of SBO. Therefore, operators should be aware of the possibility of SBO when treating the main vessel with a BVS, even in SB with reference vessel diameters of more than 1.0 mm.

Optical coherence tomography (OCT) imaging showed that the bioresorbable vascular scaffold struts covered completely the orifice of side branches (SB1 and SB2) (A to C), despite the bioresorbable vascular scaffold being well expanded with no malapposition and an acceptable lumen area. Abbreviations as in Figure 1.

Footnotes

Dr. Latib serves on the advisory board for Medtronic. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose. Drs. Sato and Panoulas contributed equally to this paper.

Received July 29, 2014.

Accepted July 30, 2014.

American College of Cardiology Foundation

References

(2013) Incidence and short-term clinical outcomes of small side branch occlusion after implantation of an everolimus-eluting bioresorbable vascular scaffold: an interim report of 435 patients in the ABSORB-EXTEND single-arm trial in comparison with an everolimus-eluting metallic stent in the SPIRIT first and II trials. J Am Coll Cardiol Intv6:247–257.